SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb8af3652e63c7e549fbf16f07acef8d6fc437d06efe8ef2b468d06bd42bb7e' 
  AND token = 'Qj+vJnOH93AmZBUw+HxrGYhAs8YdVqIxpF7bU596cHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}